Their first major hit was HMS Pinafore (1878), satirizing the Royal Navy and the British obsession with social status. The Pirates of Penzance (1879), written in a fit of pique at American copyright pirates, also poked fun at romantic melodrama, sense of duty, family obligation, and the relevance of a liberal education. Patience (1881) satirized the aesthetic movement in general and the poet and aesthete Oscar Wilde in particular. Iolanthe (1882) pokes fun at English law and at the House of Lords. Ruddigore (1887) is a topsy-turvy take on the Victorian Melodrama, and viciously satirizes that entire genre. The Gondoliers (1889) pokes fun at the plot devices of opera in the setting of a kingdom run by a pair of kings who believe in "republican equality". Their most popular work was The Mikado (1885), where English bureaucracy was made fun of in a Japanese setting.
Gilbert's plots remain perfect examples of "topsy-turvydom," in which primeval fairies rub elbows with English lords, gondoliers ascend to the monarchy and pirates reconcile with major-generals. Gilbert's lyrics employ double (and triple) rhyming and punning, and served as the very model for such 20th century Broadway lyricists as Cole Porter, Ira Gershwin, and Lorenz Hart. Sullivan, a classically-trained musician who devoted much of his career to religious hymns and grand opera, contributed catchy melodies which were also emotionally moving. As seamless as their onstage collaboration was, Gilbert and Sullivan were temperamentally incompatible, and their partnership was frequently ruptured. Their last joint work, The Grand Duke, opened in 1896, and the sickly Sullivan died four years later.
Their works were originally produced by British impresario Richard D'Oyly Carte, considered by some to be the third member of this partnership, who built the Savoy Theatre in London to present their operas, and formed the D'Oyly Carte Company, which would perform the Savoy Operas with exacting detail until 1982. The Gilbert and Sullivan operas were even more popular abroad, and many American cities saw amateur and professional Gilbert and Sullivan performing groups. (And still do! As of 2002, a web search on "Gilbert and Sullivan Society" reveals tens of thousands of links in England, the U.S, and Canada, and not just cities...). It can be argued that these operas and the Mikado in particular were instrumental in giving the particular shape to American musical of the 20'th century. The article by H.L. Mencken written in 1910 makes for interesting reading.
Into the 21st century, the Gilbert and Sullivan operas remain popular. The 1999 Mike Leigh film Topsy-Turvy presented the creation of "The Mikado" to critical acclaim.
The works of Gilbert and Sullivan are frequently parodied or pastiched; a notable example of this is Tom Lehrer's performance of the "Major General's Song", (from the operetta The Pirates of Penzance), with the chemical periodic table of elements set to Sullivan's original music. (see Elements song)